Biventricular Versus Right Ventricular Pacing in Heart Failure Patients With Atrioventricular Block (BLOCK HF)

Inclusion Criteria:

Subject has standard class I or class IIa indication for pacemaker implantation in accordance with ACC/AHA/HRS guidelines
Subjects diagnosed with atrioventricular (AV) block. An AV block is a disturbance when the heart's natural pacemaker sends a message from the atrium (top part of heart) to the ventricle (bottom part of heart) and the message is partially or totally blocked
Subject is receiving first time implant
Subjects with heart failure but no symptoms of it (New York Heart Association [NYHA] Class I), or subjects with mild heart failure that only sometimes interferes with their daily activities (NYHA Class II), or subjects with heart failure that severely limits daily activities (NYHA Class III)
Subjects with documented reduced heart pumping function (left ventricular ejection fraction ≤ 50%) within past 90 days
Subject is at least 18 years old
Subject or authorized legal guardian or representative has signed and dated the Informed Consent
Subject is able to receive a pectoral implant
Subject is expected to remain available for follow-up visits at the study center
Subject is willing and able to comply with the protocol

Exclusion Criteria:

Subject has ever had a previous or has an existing device implant
Subjects with some forms of chest pain or myocardial infarction (heart attack) within the past 30 days
Subjects with coronary bypass within the past 30 days
Subjects with stent within the past 30 days
Subjects with valve repair or replacement within the past 6 months or is indicated for repair or replacement
Subjects with a mechanical right heart valve
Subject is indicated for a biventricular pacing device (CRT-P or CRT-D devices)
Subject is enrolled in a concurrent study which may confound the results of this study (co-enrollment in any concurrent clinical study requires approval of the study manager)
Subject is pregnant, or of child bearing potential and not on a reliable form of birth control
Subjects with a previous heart transplant
Subjects has been classified as NHYA Functional Class IV within prior 90 days (subjects with severe heart failure and should always be resting)
Subject, legal guardian or authorized representative is unable or unwilling to cooperate or give written informed consent